Compositions containing difluoromethane and fluorine substituted olefins

Abstract

Compositions comprising multi-fluorinated olefins and HFC-32 are disclosed. Such compositions are useful particularly for in stationary refrigeration and air conditioning equipment.

What is claimed is: 
     
       1. A heat transfer composition comprising a refrigerant composition consisting of:
 (a) difluoromethane (R-32) in an amount of about 35 weight percent; and 
 (b) 2,3,3,3-tetrafluoropropene (HFO-1234yf) in an amount of about 65 weight percent; wherein said refrigerant has an evaporator glide and a compressor glide of less than about 5° C. 
 
     
     
       2. A method of transferring heat to or from a fluid or body comprising causing a phase change in a refrigerant composition according to  claim 1  and exchanging heat with said fluid or body during said phase change. 
     
     
       3. A refrigeration system comprising a heat transfer composition in accordance with  claim 1 , said system being selected from the group consisting of automotive air conditioning systems, residential refrigerator systems, residential freezer systems, commercial refrigerator systems, commercial freezer systems, chillers, heat pump systems, and combinations of two or more of these. 
     
     
       4. The heat transfer composition of  claim 1  wherein said refrigerant has a GWP of less than 400. 
     
     
       5. A method of providing cooling in a system of the type containing or designed to contain R-404A and comprising a compressor, a condenser, an evaporator and a heat transfer composition in the system, the method comprising:
 a. circulating said heat transfer composition in the system, wherein said heat transfer composition comprises a refrigerant consisting of:
 (i) difluoromethane (R-32) in an amount of 35 weight percent; and 
 (ii) 2,3,3,3-tetrafluoropropene (HFO-1234yf) in an amount 65 weight percent; and 
 b. providing cooling by evaporating said refrigerant in said condenser, wherein said system operates with a system capacity of at least about 95% relative to that of R-404A and wherein the system operates with an evaporator glide of about 5° C. or less. 
 
 
     
     
       6. The method of  claim 5  wherein said composition has a capacity of about 100% of R-404A. 
     
     
       7. The method of  claim 5  wherein said system operates with a condenser glide of 2° C. or less and an evaporator glide of 2° C. or less. 
     
     
       8. An air conditioning system of the type comprising a compressor, a condenser, an evaporator and a heat transfer composition in the system, the improvement comprising said heat transfer composition comprising a refrigerant consisting of:
 (i) difluoromethane (R-32) in an amount of 35 weight percent; and(ii) 2,3,3,3-tetrafluoropropene (HFO-1234yf) in an amount of 30 weight percent, wherein in operation said system operates with a capacity of at least 95% relative to that of R-404A. 
 
     
     
       9. The air conditioning system of  claim 8  wherein said system operates with an evaporator glide of 5° C. or less. 
     
     
       10. The air conditioning system of  claim 9  wherein said refrigerant has a GWP of less than 400. 
     
     
       11. The air conditioning system of  claim 8  wherein said system operates with a condenser glide of 2° C. or less and an evaporator glide of 2° C. or less.